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[dinosaur] Helsinki Paleontologist's Proudly Present: News from Her Majesty's Secret Service


Non-dinosaurian news, but still might be of interest... :)

Žliobaitė, I., Fortelius, M. & Stenseth, N. C., 2017: Reconciling taxon 
senescence with the Red Queen’s hypothesis.
--Nature: in press [doi: 10.1038/nature24656]

Abstract: "In the fossil record, taxa exhibit a regular pattern of waxing and 
waning of occupancy, range or diversity between their origin and extinction. 
This pattern appears to contradict the law of constant extinction, which states 
that the probability of extinction in a given taxon is independent of that 
taxon’s age. It is nevertheless well established for species, genera and higher 
taxa of terrestrial mammals, marine invertebrates, marine microorganisms, and 
recent Hawaiian clades of animals and plants. Here we show that the apparent 
contradiction between a stochastically constant extinction rate and the 
seemingly deterministic waxing and waning pattern of taxa disappears when we 
consider their peak of expansion rather than their final extinction. To a first 
approximation, we find that biotic drivers of evolution pertain mainly to the 
peak of taxon expansion, whereas abiotic drivers mainly apply to taxon 
extinction. The Red Queen’s hypothesis, which emphasizes biotic interactions, 
was originally proposed as an explanation of the law of constant extinction. 
Much effort has since been devoted to determining how this hypothesis, 
emphasizing competition for resources, relates to the effects of environmental 
change. One proposed resolution is that biotic and abiotic processes operate at 
different scales. By focusing attention on taxon expansion rather than 
survival, we resolve an apparent contradiction between the seemingly 
deterministic waxing and waning patterns over time and the randomness of 
extinction that the Red Queen’s hypothesis implies."

The paper is here:

University of Helsinki newsflash:


--Mikko Haaramo

Mikko K. Haaramo
Vertebrate paleontologist (freelance)
aff. Department of Geosciences and Geography
P.O.Box 68 (Gustaf Hällströmin katu 2b)
FIN-00014  University of Helsinki

tel: +358-2941-50821
email: mikko.haaramo(at)helsinki.fi